I can't find my child, have never seen her. Her mother is purposely keeping her from me. What rights do I have and how do I find her.

Never married, she used me as a sprerm bank to get out of her abusive home and get on welfare. I was told she had an abortion, I was told that the child was not mine. I have been threatened with the law. Now the child is born, its been almost 2 years. I proved father status by dna, I pay child support, I have been ordered to put her on my health insurance. I have never laid eyes on her, do not know where she is, know nothing about her. I don't have a phone number. I WANT A RELATIONSHIP WITH MY DAUGHTER. I am married, have another daughter and I want my daughters to know each other. I want my daughter to know me, that I love her. Her mother had been able to hide since my daughter was born. I know her name and her birth date, that is all I know. Can you help me with visitation?